8 March 2002

New option for mastitis cure

THE first licensed antibiotic for treatment of sub-clinical mastitis in dairy cows was launched last week.

With 34% of dairy herds now in the high penalty band for somatic cell counts, sub-clinical mastitis was becoming an expensive problem, said Pharmacia cattle vet Mike Thorne.

"The cost of a milk company refusing to pick up a bulk tank full of milk could be £400-£500. Penalties of 4-6p/litre for cell counts over 400,000 and replacement costs of £750-£800 for each high cell count cow needing to be culled mean treatment of sub-clinical mastitis is worth considering."

Pharmacias new antibiotic for treating mastitis, Pirsue, is intramammary and must be administered once a day to the affected quarter for eight consecutive days. The milk withdrawal period following treatment is five days, said Mr Thorne.

"Data obtained during trials of the drug show it has a 50-70% success rate compared with 20-30% for typical three tube off-label treatments."

Trials conducted by the company showed extended antibiotic treatment was almost twice as effective at curing sub-clinical mastitis compared with shorter duration treatments, explained Pharmacias Hubert DeLuyker.

"Treating quarters with cell counts over 300,000 using two tubes of Pirsue gave a 34% cure rate compared with eight tubes, curing 60% of cases. We must face the fact that longer duration antibiotic therapy is the most effective."

But one vet in the audience questioned whether producers would consider treatment cost-effective. "For a 30-litre cow, it would cost £80 in lost milk plus a treatment cost of £20. Assuming a 50% cure rate, this works out at £200 a cure." &#42